Dr. Mark Mattson, the current Chief of the Laboratory of Neuroscience at the National Institute on Aging and also a professor of Neuroscience at The Johns Hopkins University.

He is one of the foremost researchers in the area of cellular and molecular mechanisms underlying multiple neurodegenerative disorders, like Parkinson’s and Alzheimer’s disease.

Mark and his team published several papers that discussed how fasting just twice a week can significantly lower the risk of developing both Parkinson’s and Alzheimer’s disease.

Dietary changes have long been known to have an effect on the brain. Children who suffer from epileptic seizures have fewer of them when placed on caloric restriction or fasts. It is believed that fasting helps kick-start protective measures that help counteract the overexcited signals that epileptic brains often exhibit. (Some children with epilepsy have also benefited from a specific high-fat, low-carbohydrate diet.) Normal brains, when overfed, can experience another kind of uncontrolled excitation, impairing the brain’s function, Mattson and another researcher reported in January in the journal Nature Reviews Neuroscience (source)

If you’ve ever looked at caloric restriction studies, a lot of them show prolonged lifespan as well as an increased ability to fight chronic disease.
“Calorie restriction (CR) extends life span and retards age-related chronic diseases in a variety of species, including rats, mice, fish, flies, worms, and yeast. The mechanism or mechanisms through which this occurs are unclear.”

Fasting when done correctly is great for the brain. This is evident by all of the beneficial neurochemical changes that occur in our brain when we fast. It also helps to improve stress resistance , increases neurotrophic factors, increases cognitive function , and reduces inflammation.

Your brain is challenged when you fast. Your brain responds to this challenge by adapting stress response pathways that help your brain deal with stress and lower the risk of disease. The same changes that occur in the brain during fasting mimic the changes that occur with regular exercise. They both increase the production of protein in the brain (neurotrophic factors), which in turn promotes the growth of neurons, the connection between neurons, and the strength of synapses.

Fasting can also stimulate the production of new nerve cells from stem cells in the hippocampus. Dr. Mattson also mentions ketones – an energy source for the brain’s neurons – and how fasting stimulates the improved production of ketones.
Fasting also increases the number of mitochondria in our nerve cells; this is as a result of the neurons having to adapt to the stress of fasting (by producing more mitochondria).

If the number of mitochondria in the neurons increases, it allows for the nerons to form and maintain connections between each other a lot easier, thereby improving learning and memory ability.

A study published in the June 5 issue of Cell Stem Cell by researchers from the University of Southern California showed that cycles of prolonged fasting protect against immune system damage and, moreover, induce immune system regeneration. They concluded that fasting shifts stem cells from a dormant state to a state of self-renewal. It triggers stem cell based regeneration of an organ or system.

Human clinical trials were conducted on patients who were receiving chemotherapy at the time. For long, extended periods of time, patients did not eat. This significantly lowered their white blood cell counts. In mice, fasting cycles “flipped a regenerative switch, changing the signalling pathways for hematopoietic stem cells, which are responsible for the generation of blood and immune systems.”

This suggests that fasting kills off old and damaged immune ‘fighter-cells’, and when the body rebounds it uses stem cells to create completely healthy cells, brand new cells.
The bottom line is that how you think about you’re diet is one of the most, if not the most important part of staying healthy.